Answer:
speed is the rate of change in distance thus it is scalar physical quantity
while velocity is the rate of change in displacement thus it is a vector physical quantity
Explanation:
vector physical quantity: is a quantity that requires both magnitude and direction to identify
scalar quantity: requires only magnitude to identify.
Hooke's Law states that the extension is directly proportional to the force applied so:
F/x = constant
F₁/x₁ = F₂/x₂
2 / 0.02 = 1600 / x₂
x₂ = 16 m
Elastic work = 1/2 Fx
= 1/2 * 1600 * 16
= 12.8 kJ
Answer:

Explanation:
In a LC circuit The time constant τ is the time necessary for 60% of the total current (maximum current), pass through the inductor after a direct voltage source has been connected to it. The time constant can be calculated as follows:

Therefore, the time needed for the current to reach a fraction f = 0.6(60%) of its maximum value is:

B. Fusion requires very high pressure and temperature.
Explanation:
Nuclear fusion is the combination of atomic nuclei into larger ones with the release of a large amount of energy.
Nuclear fission is the decay process in which a heavy nuclide is bombarded with with neutrons.
- Both processes release a huge amount of energy.
- But fusion produces far more energy.
- The reason why nuclear fusion is not in use is because of the high pressure and temperature needed start it.
- The activation energy is high and the energy barrier is very great.
- Only the core of the sun naturally favors fusion
learn more:
transmutation brainly.com/question/3433940
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